JP4359922B2 - Cutting tools - Google Patents

Description

  The present invention relates to a cutting tool equipped with a throwaway tip having a substantially rod shape.

  Conventionally, as a cutting tool used for inner diameter processing, as shown in FIG. 8, a generally rod-shaped (bar-shaped) throw-away tip 42 having a cutting edge 41 at one or both ends is inserted into the hole 44 of the holder 43, What is fastened with bolts 45 or the like is known.

Patent Document 1 describes that a through hole provided in an interior including a shank and a rod-shaped portion of a drill is used as an oil hole.
JP-A-8-174322

  Generally, turning is performed while applying cutting oil to the cutting blade to reduce cutting resistance and prevent temperature rise of the cutting surface due to cutting. In the case where the cutting oil is supplied separately from the conventional bar-shaped throw-away tip 42 shown in FIG. 8, there is a problem that the cutting oil does not sufficiently reach the cutting edge portion located at the tip of the tip 42. was there.

  In addition, since the cutting tool of Patent Document 1 forms a through-hole inside the rod-shaped portion of the drill, it is difficult to work or the strength of the rod-shaped portion is reduced, especially when the rod-shaped portion has a small diameter. Was remarkable.

  The present invention has been made to solve such a problem, and the object thereof is to provide a cutting tool having a substantially rod-shaped throw-away tip having a cutting edge at the tip, and the rod-shaped portion has sufficient strength. It is an object of the present invention to provide a cutting tool that is easy to process and that is capable of performing stable cutting by reliably penetrating a cutting oil into a cutting blade.

  By adopting the following configuration, the present inventors can easily form and maintain the strength of the holder and the chip, and also reliably and sufficiently infiltrate the cutting oil into the cutting edge portion of the chip, thereby stable processing. Invented that it becomes possible.

That is, in the cutting tool of the present invention, a substantially rod-shaped throw-away tip having a cutting edge at the tip is inserted from a substantially rod-like hole formed in the longitudinal direction from the holder tip, and provided at the rear end side of the substantially rod-like hole. The rear end surface of the throw-away tip is brought into contact with and fixed by a locking portion, and is formed in a part of the contact surface between the substantially rod-shaped hole of the holder and the side surface of the throw-away tip in the longitudinal direction from the tip of the holder A gap that forms the formed oil hole, and the fixing is a presser fitting that is in contact with a side surface of the throw-away tip, and a screw member that is screwed into the presser fitting and the holder to fit the two together And the presser fitting has an oil hole connecting gap portion connected to an oil hole and two blocking surfaces sandwiching the oil hole connecting gap portion, and the throw away The side of the chip Wherein the two anti-stop surface fixed in a state of being contact, is characterized in supplying the cutting oil toward the cutting edge from the holder tip through the oil hole and the oil connection clearance .

  Here, the rear end surface of the throw-away tip is formed so that the length from the tip is partially different with respect to the longitudinal direction, and the locking portion of the holder faces the cross-sectional direction of the substantially rod-shaped hole. It consists of a rod-shaped fixing pin, and fixing a part of the rear end face of the throw-away tip by abutting with a part of the fixing pin can improve the mounting position accuracy of the chip and firmly hold the chip. Desirable in terms.

  Furthermore, the fixing member abuts and fixes the side surface of the throw-away tip, and a presser fitting having a gap portion connected to the oil hole, and the presser fitting and the holder are screwed together to fit both. And fixing the throw-away tip in a state where the side surface of the throw-away tip and two resistance surfaces sandwiching the gap portion of the presser fitting are in contact with each other, and It is desirable to form a gap that forms an oil hole between the stop surfaces from the viewpoint of maintaining additional waste, cost, and holder strength without the need to separately form an oil hole.

  Furthermore, it is difficult for the cutting operation to be performed when the rear end portion of the gap forming the oil hole provided on the side surface of the throw-away tip of the holder is connected to the oil hole connecting portion drilled from the side surface of the holder. It is desirable because it can supply cutting oil without any problems.

  According to the present invention, a gap is formed in a part of the contact surface between the substantially rod-shaped hole of the holder and the side surface of the throw-away tip so as to form an oil hole formed in the longitudinal direction from the tip of the holder. By supplying cutting oil from the tip of the holder along the surface of the tip of the tip to the cutting edge, the cutting oil can be easily formed and the strength of the holder and tip can be maintained. Therefore, stable machining is possible.

  1 is a side view of a cutting tool for inner diameter machining, which is an example in which a throw-away tip is mounted in a holder in the first embodiment of the cutting tool of the present invention, and the cutting tool of FIG. 1 and FIG. This will be described with reference to FIG.

  According to FIG. 1, a cutting tool (hereinafter simply referred to as a tool) 1 has a substantially rod-shaped hole 3 formed at the tip of a holder 2, and a throw-away tip (hereinafter simply abbreviated as a chip) in the substantially rod-shaped hole 3. ) 5 is attached.

  Here, the tip 5 has a substantially rod shape, has a cutting edge 6 on the outer side of the longitudinal tip, and has a slanting restraint surface 9a whose length from the tip is partially different from the longitudinal direction at the rear end. The slanting restraint surface 9a is in contact with and fixed to a locking portion (columnar fixing pin 10 in FIG. 1) attached to the holder 2, whereby the tip 5 The cutting blade 6 can be positioned and mounted with high precision when replacing the tip 5 and the tip 5 can be firmly restrained, so that the tip 5 rotates during cutting and the position of the cutting blade 6 is shifted or the tip 5 is displaced. It can be prevented from loosening.

  Here, according to the present invention, as shown in FIGS. 1 and 2, the oil hole formed in the longitudinal direction from the tip of the holder 2 in a part of the contact surface between the substantially rod-shaped hole 3 of the holder 2 and the side surface of the chip 5. A gap (16) forming 16 is provided, and cutting oil is supplied to the cutting edge 6 from the tip of the holder 2 through the oil hole 16 through the surface of the protruding rod-like portion 4 of the chip 5. As a result, the holder 2 and the tip 5 can be formed easily and the strength of the holder 2 and the tip 5 can be maintained, and the cutting oil can be reliably and sufficiently supplied to the cutting blade 6 of the tip 5 so that stable processing is possible.

  Here, the rear end surface of the chip 5 is formed such that the length from the front end is partially different from the longitudinal direction as in the oblique restraint surface 9a shown in FIGS. The engaging portion is composed of a rod-shaped fixing pin 10 facing substantially in the cross-sectional direction of the rod-shaped hole 3, and a part of the rear end surface of the chip 5 is in contact with and fixed to a part of the fixing pin 10. This is desirable in that the accuracy of the mounting position of the chip 5 can be improved and the chip 5 can be held firmly.

  A fixing member 11 (holding metal 12 and screw member 13) that engages both the substantially rod-like hole 3 of the holder 2 and the side surface of the chip 5 and holds the side surface while pulling the chip 5 in the rear end direction. The tip 5 is configured to be fixed, so that the tip 5 can always be mounted at a predetermined position in the tip direction of the cutting blade, and the cutting blade 6 can be positioned easily and with high accuracy. Therefore, it is possible to prevent the displacement of the cutting edge 6 and the loosening of the tip 5 by increasing the restraining force in the longitudinal direction of 5.

1 and 3, the oblique restraining surface 9a of the chip 5 is formed obliquely with respect to the longitudinal direction of the rod-shaped body, and has the merit of high dimensional accuracy in manufacture and easy manufacture. . Is 30 to 60 ° (angle between the direction S ₂ in the longitudinal direction perpendicular to the direction S ₁ and Hasukakawa Tomemen 9 chips) inclination angle θ of Hasukakawa Tomemen 9 as shown in FIG. 3, in particular 40 The angle of 50 ° is desirable from the viewpoint of improving the restraining force of the chip 5, preventing the oblique restraining surface 9 from being lost, and facilitating manufacture.

  Further, in the present invention, the shape of the rear end surface 9 is not limited to the above configuration, and as shown in FIG. 4, (a) the length in the longitudinal direction decreases stepwise, that is, the rear end surface 9 has a plurality of rear end surfaces 9. The length of the slanting restraint surface 9a is changed continuously or stepwise, such as a construction composed of surfaces, (b) a construction in which the length is continuously shortened so that the slanting restraint surface 9a forms a curved surface. Or may be any configuration such as (c) a configuration in which a recess 18 whose length in the longitudinal direction is shortened in the central portion in the cross-sectional direction, or a combination thereof, may be used. A structure that shortens the length continuously or stepwise, especially a slanted structure, in terms of accuracy, ease of manufacturing, and local stress concentration to prevent local wear and breakage. is there.

  Further, as shown in FIG. 4 (d), the rear end surface of the chip 5 has a protruding curved surface 9b having a long length in the longitudinal direction, and the engaging portion of the holder 2 is in the longitudinal direction of the substantially rod-shaped hole. The tip 5 may have a slanting locking surface 19 that is inclined obliquely, and the rear end surface of the chip 5 may be in contact with and fixed to the slanting locking surface 19. Fixing is possible. Furthermore, as shown in FIG. 4E, the rear end surface of the chip 5 and the locking portion of the holder 2 may have a normal vertical cross-sectional shape.

  Further, as shown in FIG. 5A, the rear end surface of the chip 5 has a protruding curved surface 9b whose length from the front end is partially different with respect to the longitudinal direction, and the locking portion of the holder 2 is It has an oblique locking surface (an oblique locking surface provided on the rear end side of the substantially rod-shaped hole) 19 inclined obliquely with respect to the longitudinal direction of the substantially rod-shaped hole, and the rear end surface of the chip 5 is an oblique locking surface. Even with the configuration in contact with and fixed to 19, the chip 5 can be fixed with high accuracy and high restraining force. As shown in FIG. 5A, the protruding curved surface 9b has a convex curved shape when viewed from the side of the holder and has a rectangular shape when viewed from the top of the holder, and the protruding curved surface 9b and the oblique locking surface 19 are linear. It is desirable to obtain a strong restraining force to be in contact.

  Further, as shown in FIG. 5B, the rear end surface of the chip 5 and the engaging portion of the holder 2 may be in surface contact with each other in a normal vertical sectional shape.

  Further, in FIG. 1, the fixing member 11 includes a presser fitting 12 that is fixed in contact with the side surface of the chip 5, and a screw member 13 that is screwed into the presser fitting 12 and the holder 2 to fit them together. It consists of the form to comprise. According to this embodiment, the presser fitting 12 is pulled into the rear end side by screwing the screw member 13 into the presser fitting 12, and the tip 5 is moved by the movement of the presser fitting 12. It is configured to be drawn to the rear end side of the substantially rod-shaped hole 3 of the holder 2 so as to be dragged by Further, according to the fixing member 11 of FIG. 1, the presser fitting 12 is inclined so as to approach the tip 5 side from the front end to the rear end side of the holder 2, so that the presser fitting is tightened as the screw member 13 is tightened. 12 tilts in the direction of restraining the side surface of the chip 5, so that the fixing member 11 (holding metal 12 and screw member 13) restrains the side surface of the chip 5 and securely contacts the fixed position of the rear end. it can.

  In FIG. 2, two restraining surfaces 14 are provided on the side surface of the chip 5, and the restraining surface 14 and one surface of the pressing metal 12 are fixed in contact with each other. By making the gap 16 between 14 and 14 oil holes, the chip 5 can be firmly restrained, and there is no need to separately form oil holes, so that additional machining waste, cost reduction, and strength of the holder 2 can be maintained. desirable.

  In FIGS. 1 and 2, the protruding bar-like portion 4 of the chip 5 has a circular or elliptical cross section and is formed by adding a gap 16 to the presser fitting 12 and the substantially rod-like hole 3. However, the present invention is not limited to this, and as shown in FIG. 6, a notch 20 is formed on the rod-like portion 4 side of the chip 5, and the notch 20 of the chip 25 is restrained by the presser fitting 15. Further, if the notch 20 is formed in a groove shape, there is an effect that the cutting oil can be reliably and efficiently supplied to the cutting blade 6 through the notch 20.

  Furthermore, the rear end portion 16a of the gap forming the oil hole 16 provided on the side surface of the chip 5 of the holder 2 is connected to the oil hole connecting portion 17 drilled from the side surface of the holder 2, so that cutting work is performed. It is desirable in that cutting oil can be supplied without any problem. The oil hole connecting portion 17 is connected to a cutting oil supply member 18 provided as a separate body.

  On the other hand, according to the present invention, the fixing pin 10 and the fixing member 11 of the holder 2 may be steel, but may be made of cemented carbide, cermet or ceramics in terms of wear resistance and plastic deformation resistance. Good. In addition, it is desirable that the fixing pin 10 is formed in a columnar shape that allows the portion that abuts the chip 5 to be accurately aligned and can be easily processed, but the side surface is partially cut away in the longitudinal direction and the portion that abuts the chip 5 The shape may be a plane or a polygonal prism.

  Furthermore, since the abutting portion of the fixing pin 10 is likely to be worn or deformed, it is desirable to replace the constant so that it can be replaced. A plurality of fixing pins 10 may be provided. On the other hand, the tip 5 is made of cemented carbide or cermet.

Further, according to FIG. 3, the chip 5 includes a holder restraining portion 20 fixed in the hole 3 of the holder 2 and a protruding bar-like portion 4 projecting from the holder 2, and projects beyond the diameter r ₁ of the holder restraining portion 20. Although the diameter r ₂ of the rod-shaped portion 4 is formed to be smaller, the present invention is not limited thereto, and the diameter r ₂ of the diameter r ₁ and projecting rod-like portion 4 of the holder restraining portion 20 is the same There may be. In addition, it is desirable that the ratio of r ₂ / r ₁ is 0.15 to ₁ , particularly 0.3 to 0.8, in that a small-diameter inner diameter can be processed and a restraining force of the holder 2 can be improved. Furthermore, the ratio L ₂ / L of the length L ₂ of the protruding rod-like portion 4 to the total length L of the chip 5 is 0.4 to 3, particularly 0 in that the chip 5 can be firmly restrained and the chip 5 is downsized. It is desirable that it is 5-2. In addition, the tip 5 can change the diameter and length of the protruding rod-like portion 4 according to the application, and the holder restraining portion 20 is the tip 5 having a different size by changing the diameter and length to the same. However, it can be attached using the same holder 2.

  7A, which is a view of the tip 5 of FIG. 3 as viewed from the A direction, the cutting edge 6 is slightly s = 0.1 to 0.1 from the side surface following the horizontal cutting edge 6b of the protruding bar-like portion 4. The protruding bar-like portion 4 formed at 1.0 mm outside in the cross-sectional direction is prevented from interfering with the work material. The tip of the cutting edge 6 may be a sharp edge but may be an R surface with r = 0.01 mm or less. Here, as a method of forming the cutting edge 6, after producing the rod-like protruding rod-shaped portion 4, the rear end portion of the protruding rod-shaped portion 4 from the cutting edge 6 may be polished, or cut in advance. You may produce a rod-shaped body so that the blade 6 may become larger than the rod-shaped protrusion rod-shaped part 4. FIG.

  Further, a rake face 7 is formed on the upper surface of the cutting edge 6, and the rake face 7 has a concave curved surface so as to function as a breaker. On the other hand, a front cutting edge 6 a is formed on the tip surface side of the cutting edge 6, and a side cutting edge 6 b is formed on the side face side of the cutting edge 6. Furthermore, in order to efficiently discharge chips to the portion following the cutting edge 6 on the outer periphery of the protruding rod-shaped portion 4, another notched portion 8 is cut inward from the shape assuming that the cross-section of the protruding rod-shaped portion 4 is a circle. Is formed.

  Further, the protruding bar-like portion 4 of the tip 5 is basically formed in a circular cross section, but it improves chip dischargeability during inner diameter machining and prevents interference with the work material wall after machining. Therefore, as shown in FIG. 7B, which is a BB cross-sectional view of the chip 5 in FIG. 3, the cross section of the protruding bar-like portion 4 is from an elliptical shape or a shape in which a circle or a part of the ellipse is cut out. It may be.

  Furthermore, the cutting tool of the present invention can be applied to cutting processes such as grooving, threading, drilling, etc., but particularly for inner diameter processing, in particular, the inner diameter machining of the protruding rod-like portion 4 having a minimum diameter of 4 mm or less. The tip 5 has a high strength and can achieve high-precision and high-quality processing stably even in such a minimum inner diameter processing.

It is a side view which shows the cutting tool for internal diameter processing which is a suitable example of the cutting tool of this invention. It is the arrow line view seen from the A direction of the cutting tool of FIG. It is a schematic side view of the throw away tip with which the cutting tool of FIG. 1 is mounted. (A)-(e) is the schematic which shows the modification of the rear-end surface of a throw away tip about the cutting tool of this invention. (A)-(b) is the schematic which shows the modification of the latching | locking part of a holder about the cutting tool of this invention. It is a figure which shows the modification of the cutting tool of FIG. (A) is the arrow directional view which looked at the throw away tip of FIG. 3 from A direction, (b) is BB sectional drawing of FIG. It is the schematic which shows the state which mounted | wore the holder with the conventional bar-shaped throwaway tip.

Explanation of symbols

1 Cutting tool
2 Holder 3 Substantially rod-shaped hole 4 Protruding rod-shaped part 5 Throw away tip (chip)
6 Cutting edge 6a Front cutting edge 6b Side cutting edge 7 Rake face 8 Notch 9 Rear end face 9a Oblique holding face 9b Projected curved face 10 Fixing pin 11 Fixing member 12, 15 Holding fitting 13 Screw member 14 Holding face 16 Oil hole (Gap)
17 Oil hole connecting portion 18 Oil hole supply member 19 Oblique locking surface (oblique locking surface provided on the rear end side of the substantially rod-shaped hole)
20 Holder restraint part

Claims (3)

Insert a substantially rod-shaped throw-away tip having a cutting edge at the tip into a substantially rod-shaped hole formed in the longitudinal direction from the tip of the holder,
While fixing the throw-away tip by bringing the rear end surface of the throw-away tip into contact with the engaging portion provided on the rear end side of the substantially rod-shaped hole,
A gap is formed in a part of the contact surface between the substantially rod-shaped hole of the holder and the side surface of the throw-away tip to form an oil hole formed in the longitudinal direction from the tip of the holder ,
The fixing is performed by a fixing member that includes a presser fitting that is in contact with a side surface of the throw-away tip, and a screw member that is screwed into the presser fitting and the holder to fit the two together.
The presser fitting has an oil hole connection gap portion connected to an oil hole, and two blocking surfaces sandwiching the oil hole connection gap portion,
The side surface of the throw-away tip is fixed in a state where the two blocking surfaces are in contact with each other,
Cutting tool and supplying the cutting oil toward the cutting edge from the holder tip through the oil hole and the oil connection clearance.   The rear end surface of the throw-away tip is formed so that the length from the tip is partially different with respect to the longitudinal direction, and the locking portion of the holder is fixed in a rod shape facing the cross-sectional direction of the substantially rod-shaped hole The cutting tool according to claim 1, comprising a pin, wherein a part of a rear end surface of the throw-away tip is fixed in contact with a part of the fixing pin. The rear end portion of the gap forming the oil hole provided on the side surface of the cutting insert of the holder, according to claim 1 or 2, wherein the connecting the oil hole connecting portion which is perforated from the side of the holder Cutting tools.

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